Icelandic authorities are facing pressure to step up their investigation into possible wrongdoing before the country’s banking system collapsed last year, as fresh revelations emerge about questionable lending practices that helped spawn the crisis.

Public anger has been simmering for months as Iceland conducts a postmortem on its failed banks and seeks to apportion blame for a crisis that turned one of the world’s richest nations into an economic basket case.

But a fresh wave of fury has been released this week as Icelanders digest a risk report revealing the financial secrets of Kaupthing Bank shortly before it and two other lenders crumbled last October.

The document – first exposed by Wikileaks, the whistleblower website, last weekend – showed how the bank was dangerously exposed to a handful of large clients and lent heavily to its biggest shareholders, sometimes with little or no collateral.

One of the most striking examples involved Agust and Lydur Gudmundsson, the brothers behind the Bakkavor food empire, who controlled 23 per cent of Kaupthing through their investment group, Exista. The report claimed Exista and its subsidiaries owed Kaupthing about €1.4bn ($2bn, £1.2bn) in the weeks before the crisis erupted.

Kaupthing first sought to suppress the leak with a court order that blocked Icelandic media from reporting it but the bank was forced to withdraw the injunction on Tuesday amid public outrage over the censorship.

Kristinn Hrafnsson, an investigative reporter for RUV, the Icelandic state broadcaster, the primary target of the gagging order, says the revelations intensified public pressure for people to be held accountable.

While there was no evidence of criminal wrongdoing in the leaked report, Mr Hrafnsson says Kaupthing’s prolific lending, often on lax terms, has fuelled perceptions of impropriety.

Multiple investigations are already under way by Iceland’s Financial Supervisory Authority into the meltdown, and isolated cases of alleged market manipulation and fraud have already been referred to a special prosecutor.

Kaupthing denies any wrongdoing and says its sole motivation for trying to block the leaked report was client confidentiality.

The revelations have increased scrutiny of the small band of wealthy Icelandic bankers and investors, whose aggressive international expansion left the country disastrously exposed to the global credit crunch.

Foreign hedge funds were initially blamed by many Icelanders for bringing the country to its knees, but Vilhjalmur Bjarnason, director of the Iceland Shareholders Association, says the evidence increasingly suggests home-grown culprits. “We did not need hedge funds to bring the system down. The insiders did at least as much damage,” he says.

Mr Hrafnsson says ordinary Icelanders are furious they have to pay the price for the mistakes of the business and financial elite.

Thanks to Andrew Ward and the Financial Times for covering this issue. Copyright remains with the aforementioned.